Method and apparatus for deeply discharged battery detection

Abstract

Systems and processes are provided to detect a deeply discharged rechargeable battery. A process includes initiating a processor operative to perform a function within a battery-operated device, determining a first output voltage of a battery, charging the battery with a battery charger for a duration of time between three and seven seconds in response to the first output voltage being less than a cutoff voltage, rebooting the battery-operated device, determining a second output voltage of the battery, providing a user prompt indicative of battery fault in response to the second output voltage being less than the cutoff voltage, and shutting down the battery-operated device.

What is claimed is: 
     
       1. An automated process performed by a device that is powered by a battery, the automated process comprising:
 determining a first output voltage of the battery; 
 charging the battery for a duration of time in response to the first output voltage being less than a cutoff voltage; 
 rebooting the device; 
 after the rebooting, determining a second output voltage of the battery; 
 determining if the second output voltage is less than the cutoff voltage and, if so, providing a user prompt indicative of battery fault; and 
 shutting down the battery-operated device. 
 
     
     
       2. The automated process of  claim 1  further including determining a third output voltage of the battery and wherein the shutting down of the battery-operated device is performed in response to the third output voltage being less than a cutoff voltage. 
     
     
       3. The automated process of  claim 1  wherein the cutoff voltage is zero volts and is indicative of the battery being disconnected by a cutoff circuitry in response to the battery being discharged below a lower voltage limit. 
     
     
       4. The automated process of  claim 1  wherein the user prompt is provided via a light emitting diode. 
     
     
       5. The automated process of  claim 1  wherein the battery is a lithium ion battery. 
     
     
       6. The automated process of  claim 1  wherein the cutoff voltage is indicative of the battery being discharged below a lower voltage limit. 
     
     
       7. The automated process of  claim 1  further including incrementing a counter in response to the first output voltage being less than a cutoff voltage. 
     
     
       8. The automated process of  claim 1  wherein the user prompt is provided via an audible alert. 
     
     
       9. The automated process of  claim 1  wherein the charging occurs for a duration less than ten seconds. 
     
     
       10. The automated process of  claim 1  wherein the duration of time is between three and seven seconds. 
     
     
       11. The automated process of  claim 1  wherein the duration of time is between four and six seconds. 
     
     
       12. A battery-operated device comprising:
 a battery having a voltage output; 
 a charging circuit for charging the battery in response to a charging control signal; 
 a processor configured to:
 perform a first measurement of the voltage output of the battery; 
 control the charging circuit to charge the battery for a duration of time in response to the first measurement being less than a predetermined lower voltage limit; 
 reboot the battery-operated device after controlling the charging circuit for the duration of time; 
 perform a second measurement of the voltage output of the battery after the reboot; and 
 if the second measurement of the voltage output is less than the predetermined lower voltage limit, generate a user prompt indicative of a battery fault and shut down the battery-operated device. 
 
 
     
     
       13. The battery-operated device of  claim 12  wherein the battery is a lithium ion battery. 
     
     
       14. The battery-operated device of  claim 12  wherein the processor is further operative to increment a counter in response to the first measurement of the battery voltage being less than the predetermined lower voltage limit. 
     
     
       15. The battery-operated device of  claim 12  wherein the first determination is zero volts and is indicative of the battery disconnecting the voltage output in response to a charge level being below a lower voltage limit. 
     
     
       16. The battery-operated device of  claim 12  further comprising a power supply for providing a supply voltage to the charging circuit, the processor, and a user interface. 
     
     
       17. The battery-operated device of  claim 12  wherein the charging occurs for a duration less than ten seconds. 
     
     
       18. The battery-operated device of  claim 12  wherein the charging occurs for a duration of three to seven seconds. 
     
     
       19. The battery-operated device of  claim 12  wherein the charging occurs for a duration of four to six seconds.